From a747337eb0b1c0fb7596baae1b9f5073b255597a Mon Sep 17 00:00:00 2001
From: ramon <ramonjd@gmail.com>
Date: Tue, 1 Aug 2023 10:13:35 +1000
Subject: [PATCH] Render the footer conditionally in the global styles sidebar
 component so that any side effects from the footer wrapper are not rendered,
 e.g., styles and what not Ensure that the precise bottom margin persists if
 the footer isn't rendered

---
 .../index.js                                  | 80 ++++++++++---------
 .../sidebar-navigation-screen/index.js        | 12 ++-
 .../sidebar-navigation-screen/style.scss      |  4 +
 3 files changed, 57 insertions(+), 39 deletions(-)

diff --git a/packages/edit-site/src/components/sidebar-navigation-screen-global-styles/index.js b/packages/edit-site/src/components/sidebar-navigation-screen-global-styles/index.js
index c885ca97ba7893..ce689c095d7eb5 100644
--- a/packages/edit-site/src/components/sidebar-navigation-screen-global-styles/index.js
+++ b/packages/edit-site/src/components/sidebar-navigation-screen-global-styles/index.js
@@ -108,30 +108,10 @@ function SidebarNavigationScreenGlobalStylesContent() {
 	);
 }
 
-function SidebarNavigationScreenGlobalStylesFooter( { onClickRevisions } ) {
-	const { revisions, isLoading } = useGlobalStylesRevisions();
-	const { revisionsCount } = useSelect( ( select ) => {
-		const { getEntityRecord, __experimentalGetCurrentGlobalStylesId } =
-			select( coreStore );
-
-		const globalStylesId = __experimentalGetCurrentGlobalStylesId();
-		const globalStyles = globalStylesId
-			? getEntityRecord( 'root', 'globalStyles', globalStylesId )
-			: undefined;
-
-		return {
-			revisionsCount:
-				globalStyles?._links?.[ 'version-history' ]?.[ 0 ]?.count ?? 0,
-		};
-	}, [] );
-
-	const hasRevisions = revisionsCount >= 2;
-	const modified = revisions?.[ 0 ]?.modified;
-
-	if ( ! hasRevisions || isLoading || ! modified ) {
-		return null;
-	}
-
+function SidebarNavigationScreenGlobalStylesFooter( {
+	modifiedDateTime,
+	onClickRevisions,
+} ) {
 	return (
 		<VStack className="edit-site-sidebar-navigation-screen-global-styles__footer">
 			<SidebarNavigationItem
@@ -150,8 +130,8 @@ function SidebarNavigationScreenGlobalStylesFooter( { onClickRevisions } ) {
 						{ __( 'Last modified' ) }
 					</span>
 					<span>
-						<time dateTime={ modified }>
-							{ humanTimeDiff( modified ) }
+						<time dateTime={ modifiedDateTime }>
+							{ humanTimeDiff( modifiedDateTime ) }
 						</time>
 					</span>
 					<Icon icon={ backup } style={ { fill: 'currentcolor' } } />
@@ -162,6 +142,8 @@ function SidebarNavigationScreenGlobalStylesFooter( { onClickRevisions } ) {
 }
 
 export default function SidebarNavigationScreenGlobalStyles() {
+	const { revisions, isLoading: isLoadingRevisions } =
+		useGlobalStylesRevisions();
 	const { openGeneralSidebar, setIsListViewOpened } =
 		useDispatch( editSiteStore );
 	const isMobileViewport = useViewportMatch( 'medium', '<' );
@@ -171,15 +153,28 @@ export default function SidebarNavigationScreenGlobalStyles() {
 	const { createNotice } = useDispatch( noticesStore );
 	const { set: setPreference } = useDispatch( preferencesStore );
 	const { get: getPreference } = useSelect( preferencesStore );
-	const { isViewMode, isStyleBookOpened } = useSelect( ( select ) => {
-		const { getCanvasMode, getEditorCanvasContainerView } = unlock(
-			select( editSiteStore )
-		);
-		return {
-			isViewMode: 'view' === getCanvasMode(),
-			isStyleBookOpened: 'style-book' === getEditorCanvasContainerView(),
-		};
-	}, [] );
+	const { isViewMode, isStyleBookOpened, revisionsCount } = useSelect(
+		( select ) => {
+			const { getCanvasMode, getEditorCanvasContainerView } = unlock(
+				select( editSiteStore )
+			);
+			const { getEntityRecord, __experimentalGetCurrentGlobalStylesId } =
+				select( coreStore );
+			const globalStylesId = __experimentalGetCurrentGlobalStylesId();
+			const globalStyles = globalStylesId
+				? getEntityRecord( 'root', 'globalStyles', globalStylesId )
+				: undefined;
+			return {
+				isViewMode: 'view' === getCanvasMode(),
+				isStyleBookOpened:
+					'style-book' === getEditorCanvasContainerView(),
+				revisionsCount:
+					globalStyles?._links?.[ 'version-history' ]?.[ 0 ]?.count ??
+					0,
+			};
+		},
+		[]
+	);
 
 	const turnOffDistractionFreeMode = useCallback( () => {
 		const isDistractionFree = getPreference(
@@ -226,6 +221,12 @@ export default function SidebarNavigationScreenGlobalStyles() {
 		setEditorCanvasContainerView( 'global-styles-revisions' );
 	}, [ openGlobalStyles, setEditorCanvasContainerView ] );
 
+	// If there are no revisions, do not render a footer.
+	const hasRevisions = revisionsCount >= 2;
+	const modifiedDateTime = revisions?.[ 0 ]?.modified;
+	const shouldShowGlobalStylesFooter =
+		hasRevisions && ! isLoadingRevisions && modifiedDateTime;
+
 	return (
 		<>
 			<SidebarNavigationScreen
@@ -235,9 +236,12 @@ export default function SidebarNavigationScreenGlobalStyles() {
 				) }
 				content={ <SidebarNavigationScreenGlobalStylesContent /> }
 				footer={
-					<SidebarNavigationScreenGlobalStylesFooter
-						onClickRevisions={ openRevisions }
-					/>
+					shouldShowGlobalStylesFooter && (
+						<SidebarNavigationScreenGlobalStylesFooter
+							modifiedDateTime={ modifiedDateTime }
+							onClickRevisions={ openRevisions }
+						/>
+					)
 				}
 				actions={
 					<>
diff --git a/packages/edit-site/src/components/sidebar-navigation-screen/index.js b/packages/edit-site/src/components/sidebar-navigation-screen/index.js
index d26cc4c7d62a09..f8824332f51528 100644
--- a/packages/edit-site/src/components/sidebar-navigation-screen/index.js
+++ b/packages/edit-site/src/components/sidebar-navigation-screen/index.js
@@ -1,3 +1,8 @@
+/**
+ * External dependencies
+ */
+import classnames from 'classnames';
+
 /**
  * WordPress dependencies
  */
@@ -51,7 +56,12 @@ export default function SidebarNavigationScreen( {
 	return (
 		<>
 			<VStack
-				className="edit-site-sidebar-navigation-screen__main"
+				className={ classnames(
+					'edit-site-sidebar-navigation-screen__main',
+					{
+						'has-footer': !! footer,
+					}
+				) }
 				spacing={ 0 }
 				justify="flex-start"
 			>
diff --git a/packages/edit-site/src/components/sidebar-navigation-screen/style.scss b/packages/edit-site/src/components/sidebar-navigation-screen/style.scss
index 26a30da286fc84..65fe323157b9a1 100644
--- a/packages/edit-site/src/components/sidebar-navigation-screen/style.scss
+++ b/packages/edit-site/src/components/sidebar-navigation-screen/style.scss
@@ -9,6 +9,10 @@
 	// Ensure the sidebar is always at least as tall as the viewport.
 	// This allows the footer section to be sticky at the bottom of the viewport.
 	flex-grow: 1;
+	margin-bottom: $grid-unit-20;
+	&.has-footer {
+		margin-bottom: 0;
+	}
 }
 
 .edit-site-sidebar-navigation-screen__content {